Mixing Flash with Ambient Light
The last lesson focused on learning to get a good exposure when you are using the light from your flash light as the only light to show in your image.
Today, I want to talk about using your flash when other light will be mixed into your final image. This happens often when we are outside during the daylight hours.
Mixing OCF with natural light is an extremely useful skill to learn, as most of your outside work will include some amount of ambient light. By learning to mix the two, you’ll have the option to maintain a natural look or add drama to the scene by the settings you choose with your camera and flash.
Once again, our goal is to get the right exposure. The big difference from the last lesson is that now we will need to expose correctly for the background as well as the subject.
1. Expose for your background.
At this point, keep your flash off. First, meter for your background with your ISO at 100 and your shutter speed at your camera's max sync speed. This number is different depending on your camera's brand; Canon is 1/200 and Nikon tends to be a bit higher but close to the same number.
With my triggers, I have the ability to use a much higher shutter speed (High-Speed Sync) which allows me a wider range of available apertures. You can also use a ND filter to block light, this will allow you to use wider apertures in bright situations. If that sounds confusing don't worry, we will talk about that other time. For today, just work with what you have.
Take a test shot. Ignore your subject and focus on if your background is correctly exposed. Adjust your aperture if you need to make any changes. Once you have your background exposed to your liking, turn on your flash.
2. Add Flash.
Don't be afraid just to start somewhere when choosing your flash power setting. As you gain confidence in mixing your flash with ambient light you will have a good idea of what your flash settings will need to be before you even take the first picture. For now, just set it at 1/16 power and adjust accordingly if your subject is too bright or dark.
You're done and I hope that was easier than you expected.
When dealing with flash, a good rule of thumb is that your shutter speed controls your ambient light/background while your aperture affects your subject (area lit by flash).
Natural Light
Exposed for subject highlights.
Exposed for Sky
From looking at my natural light image, I knew that I wanted to retain the look of the light on my daughter's face while bringing in more detail from the sky.
Image exposed for background and subject.
At this point, I just needed to add in a small amount of flash to expose my subject while retaining the detail of the sky.
Pull-Back
Here is a partial pullback.
You can see the modifier, the 28” Glow foldable beauty dish, in the upper right corner.
With experience you will be able to shape the light to be dramatic or very natural. If you are looking for a practical exercise to get you started, you can try this:Exercise: Getting Comfortable with Ambient Light
I would recommend you do this exercise early or later in the day as there are challenges of mid-day, full-sun, light that I am not going to cover right now.
Gather three different images from the same time/ambient light/location.
For your first image, expose for your subject. Basically, take the best natural light picture that you can.
For your second image, expose for your sky according to step #2 from above. This is open to your creative vision, some people may want darker skies than others, do what you prefer for your image, just make sure it is intentional.
For your final image add your flash to correctly expose your subject.
When dealing with flash, a good rule of thumb is that your shutter speed controls your ambient light/background while your aperture affects your subject/area lit by flash.
For bonus points, take a pullback to show your light setup and share it with us in this course.
If you have questions, feel free to comment and I would love to see what you create with your flash!